Re: [PATCH v5 2/4] mm: Provide kernel parameter to allow disabling page init poisoning

[Dave Hansen]

On 09/26/2018 08:24 AM, Alexander Duyck wrote:
> With no options it works just like slub_debug and enables all
> available options. So in our case it is a NOP since we wanted the
> debugging enabled by default.

Yeah, but slub_debug is different.

First, nobody uses the slub_debug=- option because *that* is only used
when you have SLUB_DEBUG=y *and* CONFIG_SLUB_DEBUG_ON=y, which not even
Fedora does.

slub_debug is *primarily* for *adding* debug features.  For this, we
need to turn them off.

It sounds like following slub_debug was a bad idea, especially following
its semantics too closely when it doesn't make sense.